BoostinFC

ALright, elevation is 1,500ft above sealevel

6:10PM
11/MAY/2007
Temp... 76 F
Absolute Barometer ... 28.20

R/T... .774
60'... 2.295
330... 6.357
1/8... 9.763
MPH... 74.20
1000... 12.558
1/4... 14.930
MPH... 94.94

I'd like to scan the slip and post it, but down here at college thats hard to come by. The worst part is, everytime i got to the burn-out box my SAFC showed that my engine was knocking everytime, so over-heating seemed to be a problem with waiting in long staging lines (even though my temp gauge read 180). NExt mods is to remove the clutch fan and get a more efficient, electric fan which should help my heating issues. My last run i pulled through the staging lanes (took about 30 mins each run) with the hood open to see if it helped, and it did, but this was after the track was cold so I spun them through first and only got 15.649 sucks. At least i got into the 14's

Oh, by the way: 1987 Turbo II, 3" downpipe, race pipe, 2 1/2 Borla Exhaust, Cone filter right on the flapper, thats it. Boosted to 11psi even though normally it boosts to 14. A little too humid.

jkimbro

iTrader: (3)

No fuel mods? You're abusing that motor.

BoostinFC

oh, might I add SAFC II adding fuel appropriately. Me and my friend had twin 87 TII's and his was running so rich he was leaning his out. I dont have money for a wideband yet so I have it set to gradually add more fuel starting at 3,200 up to 5% more at 7K. No abuse I can see. Rotary performance says OEM will support 300EHP no problem http://www.rx7.com/store/rx7/fcfuel.html

BoostinFC

and some research shows our stock cooling system is pretty efficient, so alcohol injection seems to be in my future. An electronic boost controller is too, if i can find some of those money trees

eriksseven

iTrader: (6)

With full exhaust and the stock fuel-system, you should really keep it below 10psi. The SAFC is a start, but you should think about at least upgrading to an FD fuel-pump. Don't believe that website that says the stock 550's can support 420hp... That's ridiculous.

BoostinFC

A walbro and FPR are on the checklist, and I dont believe that website either (yet I wouldnt be suprised if all four injectors at 100%DC could handle close to their #'s), but im pushing maybe 210, which isnt much over stock (187) (That number is from a cheesy G-tech which i REALLY dont believe, but i guessed 210 and it said 213, so 210 sounds close). At 14psi @ 7K my AFM still is only at 80%, so our fuel systems cant be that pathetic (assuming the metering device is the weaker link than the fuel system, as it is in most manufacturers). But i understand your concern, and It is very much my concern as well. ITs just my friends 87TII was running so damn rich with NO adjustments (12:1)he was running 25PSI for two weeks (stock turbo) when an apex seal finally gave - not because of detonation - but because the factory apex seals cant handle [reliably] the pressure and resulting compression force over 15psi for an extended period of time. Soon ill be able to afford a wideband.

P.S. I think my friend is an idiot too, and at the track, when he said "what the hell are you doing, turn your boost up".... I just walked away

Wizz

How the hell do you get 25 psi out of the stock turbo?

Do your fuel mods and get a TID.

eriksseven

iTrader: (6)

The FPR isn't necessary with the stock turbo. Larger CC secondary injectors should go in well before an FPR. The AFM does not meter fuel--it meters air. The stock AFM does not become a restriction until 350whp+, and has nothing to do with the ability of your fuel-system.

Also 12:1 is not rich for a turbo rotary... Ideally, you'd want to tune for mid-11's in a modified turbo Rx7.

And no, you're wrong about your friend blowing his motor... Mazda apex-seals can handle 40+psi of boost and are still considered better than many aftermarket seals. If your friend was actually able to get that turbo to push 25psi--he is a complete idiot who needs to have his car taken away from him. He knows nothing about rotary engine's or tuning them... The stock HT-18 turbo's maximum efficiency is around the 12-14psi range. And yes, he probably experienced massive detonation that (in turn) shattered some apex-seals...

classicauto

iTrader: (3)

Probably from the 180 degree air that the HT-18 would be pushing at 25psi

can't handle 25psi.......

RotaryEvolution

iTrader: (30)

yea, don't listen to your friend... or that website.

stock TII fuel pump is good for about 240 WHP before it starts to drop pressure(from testing on my own car), stock injectors even close to 100% DC can only handle close to what the fuel pump can but can squeeze a little more out of them with higher fuel pressure and a more efficient pump.

adding 5% at 11psi still doesn't seem like enough though it probably is close enough to hold the engine together but ideally it should be tuned. the stock turbo only puts out about 12psi of efficient air anyways so you don't need to push it much farther than that.

BoostinFC

Alright guys, thank you everyone who has replied, this is the whole reason I post on here so I can learn from the veterans since this is my first RX7. I love learning, and of course, I cannot afford to blow up my motor so I will add more fuel ( for now)and tune as soon as I can, I just wish I could afford a good wideband sooner than a couple months. I appreciate all of your inputs, i have certainly learned alot so far from you guys, I will keep you all updated. Thanks!


-Matt

P.S. In the meantime while I am forced to tune my blind, does anyone have recommended Fuel Increments for my SAFC? I know this is the wrong way to do things, but I dont have much of a choice untill I get a wideband. With the mods I have, the thing boosts to 14psi out of control, meaning I do not have a boost controller, just with the mods, this is hwat it boosts to. I believe this is because the CorkSport Downpipe (DONT buy) has a plate (bolts between DP and Turbo)which partially blocks my wastegate (I was checkin it out when I pulled my turbo to inspect it). Does anyone have any good recommendations of a down pipe which has an integrated wastegate section, or any good ideas to make an external dump? The plate which blocks my wastegate from opening 100% is the stupidest thing I've ever seen.

Once again, criticism is accepted. Thanks guys!